Apple's ploy to gain browser market share by pushing Safari to users with an update tool normally used for security fixes failed to boost its overall share, a Web metrics company said yesterday.

Instead, Safari's share fell last month to 5.5%, down from March's 5.8%, while Microsoft's Internet Explorer increased its dominance by growing to 76% from March's 74.8%. It was the first time Internet Explorer (IE) gained share since October 2007.

Firefox's share also fell in April by nearly a percentage point from the month prior. The open-source browser, which had accounted for 17.8% of the usage market in March, dropped to 17% last month. It was the largest one-month drop in the browser's market share since May 2007, and put an end to a run of five consecutive months of gains.

IE, meanhwhile, reversed its long slide last month. In April, Microsoft's browser increased its market share by more than a percentage point over March, the largest gain since Net Applications began publishing browser data in May 2006. Ironically, the bulk of IE's increase in April came from the older IE6, which boosted its share from 28.9% to 30%. The newer IE7, meanwhile, climbed just 0.1% during the same period.

Both Mozilla and Microsoft are working on the next versions of their respective browsers. Firefox 3.0, which is still in testing, is expected to go final before the end of June, while IE8 will wrap sometime this year, Microsoft has said.